House edge is the way in which casino do make money and since they are running a business so they need to have an advantage as well since they have to pay salary to staff, security , rentals etc which all involved cost.
We must accept the fact that gambling casinos needs this to sustain their operations I'm ok with it as long as there are people winning on their platform and they are willing to give their cash out, this has been our biggest worry on every gambling casinos, not giving our winning when we rightly deserve it, transparency and reputation are two of the features gambling sites should maintain.
So very necessary for users to play on reputed and trustworthy sites which have a good reputation on forum and paying them on their win. Some of the gambling sites are running from years now so they will not do anything which can destroy their reputation so users can be relaxed and play without any worries of not getting paid in the end. Need to choose such gambling sites wisely.